A common method of controlling a MOSFET in “high-side” connected circuits requires the use of a voltage isolating pulse transformer in the gate-to-source biasing circuit. “High-side” refers to a circuit configured with the MOSFET switch connected between the supply voltage and the load impedance; it is connected to the higher voltage side of the load impedance. A “low-side” connected MOSFET does not, typically, present damaging gate-to-source voltages, but then one end of the load impedance is connected to the high side of the supply voltage. A voltage isolating pulse transformer can be used in “high-side” circuits; it allows the gate-to-source circuit to float (electrically) near the source potential which prevents the gate-to-source voltage from reaching device damaging values. Disadvantages of simple transformer biasing include a lower limit to the frequencies of useful operation (this precludes DC operation), pulse transformers designed to isolate high voltages can be expensive and unreliable, and transformers capable of low frequency operation are large and heavy.